From 21ca254448dfbb4134e40f1e9ba9614259c86299 Mon Sep 17 00:00:00 2001
From: Keith Rarick <kr@xph.us>
Date: Sat, 26 Feb 2011 04:10:41 -0800
Subject: [PATCH] don't use EV_PERSIST for listen socket

---
 beanstalkd.c |  8 ++++++--
 conn.c       |  2 +-
 dat.h        |  6 +++---
 net.c        | 42 +++++++-----------------------------------
 prot.c       | 20 +++++++++++---------
 5 files changed, 28 insertions(+), 50 deletions(-)

diff --git a/beanstalkd.c b/beanstalkd.c
index b6d21e03..17f147ce 100644
--- a/beanstalkd.c
+++ b/beanstalkd.c
@@ -259,7 +259,7 @@ opts(int argc, char **argv)
 int
 main(int argc, char **argv)
 {
-    int r;
+    int r, l;
     struct event_base *ev_base;
     struct job binlog_jobs = {};
 
@@ -285,13 +285,17 @@ main(int argc, char **argv)
 
     r = make_server_socket(host_addr, port);
     if (r == -1) twarnx("make_server_socket()"), exit(111);
+    l = r;
 
     if (user) su(user);
     ev_base = event_init();
     set_sig_handlers();
     nudge_fd_limit();
 
-    unbrake((evh) h_accept);
+    r = listen(l, 1024);
+    if (r == -1) twarn("listen()");
+    accept_handler = (evh)h_accept;
+    unbrake();
 
     binlog_jobs.prev = binlog_jobs.next = &binlog_jobs;
     binlog_init(&binlog_jobs);
diff --git a/conn.c b/conn.c
index deda8c02..0f059c2a 100644
--- a/conn.c
+++ b/conn.c
@@ -282,7 +282,7 @@ conn_close(conn c)
 
     cur_conn_ct--; /* stats */
 
-    unbrake(NULL);
+    unbrake();
     remove_waiting_conn(c);
     conn_remove(c);
     if (has_reserved_job(c)) enqueue_reserved_jobs(c);
diff --git a/dat.h b/dat.h
index 1b3746fd..4bcd9497 100644
--- a/dat.h
+++ b/dat.h
@@ -281,9 +281,9 @@ void prot_replay_binlog(job binlog_jobs);
 
 int make_server_socket(char *host_addr, char *port);
 
-void brake();
-void unbrake(evh h);
-void set_main_timeout();
+void unbrake();
+extern int listening;
+extern evh accept_handler;
 
 
 extern char *binlog_dir;
diff --git a/net.c b/net.c
index 00209c2e..c76c03d5 100644
--- a/net.c
+++ b/net.c
@@ -32,8 +32,8 @@
 
 static int listen_socket = -1;
 static struct event listen_evq;
-static evh accept_handler;
-static int brakes_are_on = 1;
+evh accept_handler;
+int listening = 0;
 
 int
 make_server_socket(char *host, char *port)
@@ -130,45 +130,17 @@ make_server_socket(char *host, char *port)
 }
 
 void
-brake()
-{
-    int r;
-
-    if (brakes_are_on) return;
-    brakes_are_on = 1;
-    twarnx("too many connections; putting on the brakes");
-
-    r = event_del(&listen_evq);
-    if (r == -1) twarn("event_del()");
-
-    r = listen(listen_socket, 0);
-    if (r == -1) twarn("listen()");
-}
-
-void
-unbrake(evh h)
+unbrake()
 {
     int r;
+    struct timeval tv;
 
-    if (!brakes_are_on) return;
-    brakes_are_on = 0;
+    if (listening) return;
+    listening = 1;
 
-    accept_handler = h ? : accept_handler;
-    event_set(&listen_evq, listen_socket, EV_READ | EV_PERSIST,
+    event_set(&listen_evq, listen_socket, EV_READ,
               accept_handler, &listen_evq);
 
-    set_main_timeout();
-
-    r = listen(listen_socket, 1024);
-    if (r == -1) twarn("listen()");
-}
-
-void
-set_main_timeout()
-{
-    int r;
-    struct timeval tv;
-
     timeval_from_usec(&tv, 10 * MSEC);
 
     r = event_add(&listen_evq, &tv);
diff --git a/prot.c b/prot.c
index 9b2689d9..250b4665 100644
--- a/prot.c
+++ b/prot.c
@@ -1744,7 +1744,7 @@ h_delay()
         }
     }
 
-    set_main_timeout();
+    unbrake();
 }
 
 void
@@ -1755,30 +1755,32 @@ h_accept(const int fd, const short which, struct event *ev)
     socklen_t addrlen;
     struct sockaddr_in6 addr;
 
-    if (which == EV_TIMEOUT) return h_delay(), set_main_timeout();
+    listening = 0;
+
+    if (which == EV_TIMEOUT) return h_delay(), unbrake();
 
     addrlen = sizeof addr;
     cfd = accept(fd, (struct sockaddr *)&addr, &addrlen);
     if (cfd == -1) {
         if (errno != EAGAIN && errno != EWOULDBLOCK) twarn("accept()");
-        if (errno == EMFILE) return brake(), v();
-        set_main_timeout();
+        if (errno == EMFILE) return;
+        unbrake();
         return;
     }
 
     flags = fcntl(cfd, F_GETFL, 0);
-    if (flags < 0) return twarn("getting flags"), close(cfd), set_main_timeout();
+    if (flags < 0) return twarn("getting flags"), close(cfd), unbrake();
 
     r = fcntl(cfd, F_SETFL, flags | O_NONBLOCK);
-    if (r < 0) return twarn("setting O_NONBLOCK"), close(cfd), set_main_timeout();
+    if (r < 0) return twarn("setting O_NONBLOCK"), close(cfd), unbrake();
 
     c = make_conn(cfd, STATE_WANTCOMMAND, default_tube, default_tube);
-    if (!c) return twarnx("make_conn() failed"), close(cfd), brake();
+    if (!c) return twarnx("make_conn() failed"), close(cfd), v();
 
     dbgprintf("accepted conn, fd=%d\n", cfd);
     r = conn_set_evq(c, EV_READ | EV_PERSIST, (evh) h_conn);
-    if (r == -1) return twarnx("conn_set_evq() failed"), close(cfd), brake();
-    set_main_timeout();
+    if (r == -1) return twarnx("conn_set_evq() failed"), close(cfd), v();
+    unbrake();
 }
 
 void